Fake frost?

I've heard of pros using egg white, icing sugar and flour to create fake frost on flowers, etc. Anyone done this or got a better tip?

A good stage design book will have a lot of suggestions for the larger props you might use. I vaguely recall some kind of salt (not NaCl, maybe alum or borax?) for riming windows. Dries into large crystals. Certainly they won't have tips like Elmers for milk droplets, though.